Chiral analysis of bambuterol, its intermediate and active drug in human plasma by liquid chromatography–tandem mass spectrometry: Application to a pharmacokinetic study

•Chiral analysis of bambuterol, its intermediate and active drug in human plasma.•The method achieved the highest sensitivity and the fastest analysis speed.•Application to a clinical pharmacokinetics study of rac-bambuterol.•Stereoselective metabolism exists in the metabolic process of rac-bambuterol.